- Introduce DC_vPrepareDCsForBlit and DC_vFinishBlit and use them in NtGdiAlphaBlend
- Get rid of now unnecessary call for MouseSafetyOnDraw{Start,End} in IntEngAlphaBlend
- Yet Another Rewrite of GDIOBJ_LockMultipleObjs :-/ and use it in NtGdiAlphaBlend